In short. The south of Bali has two seasons: from December to March there are 200–500 mm of rain a month, most in January, and from June to September up to 50 mm, with April and May in transition. The average temperature at Ngurah Rai station in 2023 was 26–28.6°C, coolest in August and warmest in November, with sunshine from 52% of the time in February to 99% in October. From November to April the wind is westerly and from June to October south-easterly, and in the dry season waves in the south can be high. In the mountains the rains come earlier (in the 2026/2027 season from 21 to 30 November near Bedugul) and in the north later and heavier. The beach and trips around the island are best from May to October. In the rainy season, allow extra time for travel and bring a raincoat.
Where the numbers come from. The Ngurah Rai station near the airport in the south of the island makes observations for BMKG, and the Bali Climatology Station publishes them as an annual summary. We used the summary for 2023: temperature, humidity, sunshine and wind by month. Rainfall in a single year shows individual spikes, so for typical rainfall we looked at the BMKG maps of average rainfall for 1991–2020 in the same summary. We read values on the maps by the colour of the scale classes, so they are given as ranges and may be off by one step.
Two seasons. According to BMKG maps, the south of Bali gets roughly 200–500 mm a month from December to March, with the most in January. In April the normal is already about 100–150 mm, in May 20–100, and from June to September the south gets up to 50 mm a month, almost nothing in August. In October the normal rises to 50–150 mm, in November to 100–200 and in December to 300–400. The dry period can be taken as May to October, with April and November in transition.
Temperature and humidity. According to the Ngurah Rai table for 2023, average air temperature stayed within 26.0–28.6°C: August was the coolest and November the warmest. The average daytime maximum ranged from 28.6°C in July to 31.9°C in November, and the night minimum from 24.1 to 26.0°C. Air humidity was between 81 and 85 percent in all twelve months. We did not find sea temperature in an official source, so we do not give a figure.
Sun and rain in real numbers. In 2023 the sun shone from 52 percent of the time in February to 99 percent in October. The rainiest month of that year was February: 468.5 mm and 25 rainy days. In September, though, only 2 mm fell, and the rainfall row for October shows a dash. This is a single calendar series and other years will differ, but it shows the gap between the seasons.
Wind and waves. According to station data for 2023, from November to April the wind was most often westerly, in May easterly, and from June to October south-easterly. The maximum gust of the year, 43.2 km/h, came in February, from the west. Waves in the south of the island grow in the dry season: in August 2026 BMKG warned of waves of 4–6 metres in the waters south of Bali and in the southern part of the Lombok Strait for 10–13 and 13–16 August (Kompas and IDN Times Bali). The causes given were wind and the phases of the moon, perigee on 10 August and new moon on 13 August, and BMKG noted a risk for shipping. For beach flags and currents, see our ocean guide.
South, mountains and north.
- South: Kuta, Seminyak, Canggu, Bukit, Sanur. Dry from May to October, main rains from December to March. The BMKG forecast for the 2026/2027 season puts the start of rains in the south from 11 to 20 December.
- Mountains: Bedugul, the area around Kintamani, northern Tabanan and Gianyar. Rains come earlier: according to the 2026/2027 forecast, from 21 to 30 November around Bedugul, with a peak in January or February. On BMKG maps, the highest rainfall classes, above 500 mm, appear in the mountains in January and February. We did not find an official source on how much cooler the mountains are than the coast.
- North: Lovina and the Buleleng coast. In September the northern coast falls into the driest class on the normal map. According to the 2026/2027 forecast, rains in the north begin from 21 to 31 December, and BMKG expects more rain than usual in the north.
When to go for what.
- Beach and swimming: May to October, when rainfall is lowest and sunny days are most frequent. Waves in the south can be high at the same time, so watch the flags and BMKG warnings.
- Trips around the island and temples: the most reliable window is May to September, when the normal map shows the least rain.
- Rainy season: December to March. In the south there are usually downpours, roads in the mountains see landslides, and standing water and mosquitoes appear near water.
- This year, October and November are still dry across most of the island according to the BMKG forecast.
What this means for you. Choose the month by the main purpose of your trip: the beach and sea are best from May to October, and mountains and waterfalls are more comfortable in the dry months. For the rainy season, allow extra time for travel and bring a raincoat. In any month, before you head to the coast or the mountains, check the forecast and warnings in the Info BMKG app and on bmkg.go.id. If you come in December or January, assume it will rain and plan your programme around the dry windows.